1. Field of the Invention
The present invention relates to a transparent hair rinsing composition which is excellent in rinseability and which imparts good smoothness, good suppleness and good feel to hair. More particularly, the present invention relates to a hair rinsing composition which possesses excellent transparency and stability and is characterized by a reduced solvent content. The hair rinsing composition comprises as critical ingredients (A) a quaternary ammonium salt, and (B) at least one member selected from (1) polyoxyethylene alkyl and alkenyl ethers in which the average value of the number of moles of ethylene oxide added is in the range of from 1 to 7, the unreacted alcohol content is lower than 3% and the carbon number of the alkyl or alkenyl group is in the range of from 8 to 20 and (2) polyoxyethylene alkylphenyl ethers in which the average value of the number of moles of ethylene oxide added is in the range of from 1 to 7, the unreacted alcohol content is lower than 3% and the carbon number of the alkyl group is in the range of from 6 to 12.
2. Description of the Prior Art
Hair rinsing compositions comprising, as an effective component, a quaternary ammonium salt such as distearyl dimethyl ammonium chloride have heretofore been used for minimizing such undesirable phenomena as breaking, entanglement, static charging and difficulty in the combing of washed hair. A hair rinsing agent should impart softness, smoothness and an antistatic property to washed hair. If a quaternary ammonium salt alone is employed, no satisfactory effects can be obtained with respect to softness and smoothness. Accordingly, in order to obviate this defect, oils and fats such as higher alcohols, glycerides and liquid paraffin have heretofore been incorporated in hair rinsing compositions. Hair rinsing compositions in which such oils and fats are incorporated have, in general, an opaque or pearlescent appearance.
If it is possible to form a transparent liquid when such an oily and fatty substance is used, the resulting hair rinsing composition will have a characteristic appearance and a high commercial value. Various attempts have heretofore been made to attain this goal. A most popular method comprises incorporating in a hair rinsing agent an organic solvent such as ethyl alcohol, isopropyl alcohol, ethylene glycol, propylene glycol or the like in as large an amount as 60 wt.% or more, thereby to solubilize the above-mentioned oily and fatty substance and to render the composition transparent. In addition, there can be mentioned a method in which oils and fats are solubilized by using a large amount of a highly hydrophilic non-ionic surface active agent obtained by adding 20 to 40 moles of ethylene oxide to a higher aliphatic alcohol. Moreover, there has been proposed a hair rinsing composition free of such oils and fats, which is comprised of an aqueous solution of a special water-soluble cationic surface active agent having the formula: ##STR1## wherein R' is alkyl having 16 to 18 carbon atoms.
Transparent hair rinsing compositions formed by solubilizing cationic surface active agents and oils and fats by using large quantities of organic solvents are disadvantageous because of their very high manufacturing cost. Further, the method comprising solubilizing oils and fats by using large quantities of highly hydrophilic non-ionic surface active agents is not fully satisfactory because it is difficult to maintain the resulting transparent solution system in a stable condition and the use of a large amount of a non-ionic surface active agent results in a drastic reduction of the desired rinsing effect. When there is used an aqueous solution of a special water-soluble cationic surface active agent alone, even though a transparent composition can be obtained, the product does not have a satisfactory rinsing effect. As will be apparent from the foregoing discussion, there has not been developed a transparent hair rinsing composition which has a high rinsing effect and which can be manufactured at a low cost.